Multiple !

if you had two identical magnets and put them together so that one of the south poles was in contact with the other's north pole, what would you have?
a. one magnet with a stronger north pole
b. one magnet with a stronger south pole
c. one magnet with a north pole and a south pole
d. no magnet since the two smaller magnets would lose their magnetism when combined to form a larger magnet

Aspring has a relaxed length of 33 cm (0.33 m) and its spring stiffness is 6 n/m. you glue a 76 gram block (0.076 kg) to the top of the spring, and push the block down, compressing the spring so its total length is 15 cm. you make sure the block is at rest, then at time t=0 you quickly move your hand away. the block begins to move upward, because the upward force on the block by the spring is greater than the downward force on the block by the earth. calculate y vs. time for the block during a 0.09-second interval after you release the block, by applying the momentum principle in three steps each of 0.03-second duration.